$sux = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP);
  if (!$sux) exit('create error');

  if (!socket_bind($sux, $local_ip, 2210)) exit('bind error');

  $suxref[] =& $sux;
  $ip = '';
  $port = 7130;
  do {

     socket_select($suxref, $write = NULL, $except = NULL, 5);  // sec. timout

     $z = @socket_recvfrom($sux, $buf, 9999, 0, $ip, $port);
 
     if (strlen($buf) > 0) {
       echo "\r\nRemote sent: " . $buf;
       socket_sendto($sux,  "I hear you", 9999, 0x4, $ip, $port);
       }
     }
  while(true);